Electric fuse-testing device.



C. W. MITCHELL.

ELECTRIC FUSE TESTING DEVICE,

APPLICATION FILED JUNE 2s. 1910,

Patented Apr. 4, 1911.

@www/Aoco gf Mn/"7 flttopucq CHARLES W. MITCHELL, 0F ABZRGOKIJYN, NEW YORK.

ELECTRIC FUSE-TESTING DEVICE.

Specication of Letters Patent.

yPatented Apr. 4, 1911.

Application led June 28, 1910. Serial N o. 569,354.

To all'whom it may concern: v

Be it known that I, CHARLES V. Miron- ELL, a citizen 4of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented new and useful Improvements in Electric Fuse-Test ing Devices, of which the following is a specification.

In ythose electric circuits where inclosed non-arcing fuses are employed, it is someti-mes difficult to determine which of the two fuses connected with the opposite sides oi a line circuit has been blown. Especially is this the case when there is an overload, which will destroy the fuse wire or element without igniting the powder in which -the said element is 1ncased, and it is customary to test the fuses either by touching the terminals with lthe' iingers, which vis extremely dangerous, or by using a lamp which is connected with the terminal of one fuse near the "source of supply and with the terminal of the other fuse farthest from the source of supply, so that the lamp will be connected in shunt across the line with the said other fuse in circuit, Iand should the lamp fail to glow, it is evident that the fuse being tested is destroyed. This manner of testing is accompanied .with danger, for the reason that it requires an experienced attendant to make the proper lamp connection without short circuiting the line, and furthermore, if the voltage of the circuit is beyond the capacity of the lamp, the latter will explode and endanger the eyes of the attendant, and again the intense light is trying to the eyes when the testing is carried on by a lamp.

The objects of the present invention are to overcome the diiliculties and dangers attending the testing of fuses in the old manner, by providing a lamp inclosed within a protective casing which has contact posts connected with the terminals of the lamp, and so arranged that these posts can be connected with the terminals of the fuses to test the latter. y

Another object of the invention is the provision of a testing device in which the casing or housing is cornosed of telescoping sections for accommo ating the device to fuses of different sizes, there being a novel arrangement of contacts in the casing for con` necting the lam with the contact posts.

With'these o jects in view, and others as will appear asthe description proceeds, the

invention comprises the various novel features of construction and arrangement of parts .which will be more fullywdescrihed hereinafter and set forth with p-articularity in the claims appended hereto.

In the accompanying drawings, which illustrate .one embodiment of the inventonz- Figure 1 is a central longitudinal sectionof the fuse testing device; Fig. 2 is a transverse section thereof; Fig. 3 is a erspective View of the combined lamp holding element and contact member. Y

Similar reference characters are em-f ployed to designate .corresponding parts throughout the several views.

Referring to the drawi 's, A designates the casing of the device invliich .is made in two sections 1 and 2, that are of cylindrical form and of ditfercnt diameters, so thatl one can telescope within the other, and the outer ends of the sections being closed by heads 3. These sections are clamped together by a binding screw 4, and the rsection 1 has a contact post 5, while the section 2 has a contact post 6, both extendin in thc same direction so that they cough the op osite terminals of the uses n the two'si es of a line circuit, so as to connect the tcstin device across the circuit for testing one grise at a time, thel casing being grasped in the hand while the contact posts 5 and (l are held in engagement with the fuse terminals. The post 5 is fastened to a base block 7 which is disposed within the.

casing and has .fastened thereto by a screw i) a contact strip 8 extending longitudinally of the casing and spaced from the section l, so that the section 2 can slip under the contact strip 8. Vithin the section 2 is a ,strip 10 which has its edges fastened by rivets 11 to the said section 2 and the contact strip 8 slides under and engages the bottom side of the strip 10. 0n one end of the strip 10 is a metal threaded socket 12 into which the base 13 of an inearulescent lamp 1 4: screws, and hence the filament of the lamp is con nected to the contact post 5 by the strips S and 1 0 and socket Connected with the contact post 6 is an L-shaped metal piece 16 that is electrically connected to the other terminal 15 of the lamp by an interposed spring 17 and hence it will be understood that when both Contact posts are connected with the opposite sides of a line circuit, current wil pass through the lamp and cause the filament to glow. Light emitted from the lamp passes through registering e .eigaged with slots 18 in the two sections of the casing and by this means the attendant will know that the fuse being tested is intact- F rom the foregoing description, Vtaken in connection with the accompanying drawings the advantages of the construction and et the method of operation will be readily apparent to those skilled in the art to nhich the invention relates, and While l have described the principle of operation ont' the invention, together with the device which I new consider to be the best embodiment thereof, l ldesire to have it understood that the device shown is merely illustrative and that such changes may be made when desired as are Within the scope of the claims.

lllhat I claim as new and desire to secure by Letters Patent is:

l. A fuse testing device comprising relatively adjustable members, means for supporting an incandescent lamp on one ol' the members., a contact on the lamp-supporting member electricallyy connected with one terminal of the lamp, a contact mounted on the other member and engaging the tirst-xnentioned contact, and conductors attached to the respective members 'and respectively electrically connected with the other terminal olf thc lamp and. the sccondmcntioned contact.

2. A fuse test-ing device, comprising a casing composed et slidably related parts tor lengthening or shortening the device, a lamp therein, separate contact posts projecting respectively from thc said parts of the casing, ainl means' Jlor connecting` the posts with tbe terminals of the lamp.

il. A inse Lenting device, con'iprising a casing composed of telescoping sections havmg registering light emitting openings, a

lamp in the casing, contact members connected with the respective sections of the casing, and connecting means between the members and terminals of the lamp.

-l. A fuse testing device, comprising a cas ing composed of telescoping sections, con tacts arranged within the casing and engaging ach other, means on one of the contacts for holding a lamp and to electrically connect the contact with one terminal of the same, a member connected with the other terminal of the lamp, andl contact posts fastened to the scctionsof the casing and connected respectively with said member and with one ot' the said contacts.

5. -irliise testing device, comprising a casing composed ot tclescoping sections, a con-` tact strip in one ot the sections, a contact .strip in the other section arranged to engage with the lirst-mentioned strip, a metal socket on one ot the contact strips, a lamp having its base titled into said socket, a yielding current crn'iducting connection with the lamp,l a contact post on the inner section of the caf-ling and associated with the said `yielding connection, and a contact post cured to the outer section of the casing and 'connected with the `first-mentioned contact strip, said contact posts extending laterally from the casing in the same direction.

vIn testimony whereof l alii: my signatin'c in presence of two witnesses.

v(Yllilllillh XV. MllCllELll. \l"itnesses: v

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